In the abstract the spec includes the comment
"By splittingtraditional XHTML forms into three parts --
XForms model, instance data, and user interface -- it
separates presentation from content, allows reuse...".
And in the section "2 Introduction to XForms", it states
"The primary difference when comparing XForms with HTML
Forms, apart from XForms being in XML, is the separation
of the data being collected from the markup of the
controls collecting the individual values. By doing this,
it not only makes XForms more tractable by making it clear
what is being submitted where, it also eases reuse of
forms, since the underlying essential part of a Form is no
longer irretrievably bound to the page it is used in."
And it goes on to say that existing schema re-use "obviates
duplication".
Currently, the actual implementation doesn't encourage reuse
of the model as it must be physically "cut & pasted" between
various applications (e.g. SVG & XHTML; XHTML for the
browser & XML definition within a server) and while not
being irretrievably bound, requires manual intervention for
reuse. Such re-use doesn't help in avoiding inconsistencies
as there is now duplication of the "code" with multiple
copies to manage.
There is the ability to reference external XML Schemas for
the model. There is also the abilility to reference an
external XML document for the instance. However, there
doesn't seem to be a way to reference an external model.
This could be a job for XIncludes, but support for XIncludes
is not mandated by XForms and so its value as an XForms
reuse mechanism is limited.
Thanks.
Hoylen
--
______________________________________________ Dr Hoylen Sue
h.sue@dstc.edu.au http://www.dstc.edu.au/
DSTC Pty Ltd --- Australian W3C Office +61 7 3365 4310